In In the Vineyard

There is no word for winemaker in French, Spanish, Italian or German, pointing to the ingrained belief that wine is made by nature, not by man.  The conviction has been held for centuries in the Old World-that wine is, at its core, the reflection of a place. While there is no single-word translation of terroir into English, the French will often use this one word to explain why a wine tastes the way it does, as a result of its place.  This is a basis for a present-day concern: Is industrialization muting the effect of place?  

The consumer is left to answer the questions: Did this fine wine I am enjoying come from a great vineyard in a top appellation, from a talented winemaker using some dazzling new technique, and/or from a slew of agricultural and/or processing chemicals?  

The sense of place is a concern as the world and its products become industrialized, sparking renewed interest in chemicals used in our foods, including wines.

A capstone event occurred in 1990 in theUSwith the Alar episode. Alar, a growth-regulating chemical widely used in orchards at the time, was later listed as a carcinogen. The consumer’s negative reaction was a potent catalyst for the organic food movement. The question of whether agricultural chemicals are good or bad was catapulted to the forefront inAmerica, and remains. 

Currently, there are at least two theories as to why the lack of chemicals may be a good thing (beyond the purely psychological), both relating to the production of so-called secondary plant metabolites, that is aroma, flavor and phenols.

Plants produce these for several reasons, including defending off pests and disease. Some believe that plants defended by man-made chemicals do not need to work as hard to make their own natural pesticides, such as phenolic compounds. They do not need to expel their limited energy producing as many secondary metabolites.

Another theory suggests that soils that have been significantly altered with chemicals are simpler.  While they may contain the required NPK etc., these soils may not contain all of the raw ingredient precursors that plants need to produce the vast array of secondary metabolites in optimum quantities or proportions.

There is some scientific evidence for both of these theories. For the wine industry, however, the question comes down to wine quality.  To date, there have been few studies that suggest that the lack of approved chemicals consistently produce better wines.

Not using chemicals, particularly agricultural chemicals, sounds great and is certainly consistent with our general notion of sustainability.  Unfortunately, there remains a void of scientific data suggesting that not using chemicals improves wine quality.  Unfortunately, at this time the choices may be like the old joke:

I have theory that it’s impossible to prove anything – but I cannot prove it.


Dr Bruce Zoecklein is a Professor Emeritus, Enology-Grape Chemistry Group Virginia Tech.


His Enology Notes are available at


Quick Message

We're not around right now. But you can send us an email and we'll get back to you, asap.

Start typing and press Enter to search